A uni friend of mine gave me that 12 weight puzzle ages ago, it took me hours to solve it (interestingly he was a 7 day creationist and took weeks over it and had forgot it so could not verify my answer) After scrolling through the thread I didn't see a solution so here is an answer I have just churned out in 10 minutes from a mix of memory and logic, it is about time for me to sleep so I'm half expecting an obvious flaw.

Start weighing ABCD v EFGH, call this (1) if they are the same it must be one of IJKL Weigh IJ v KC (2a) if (2a) balances it must be L, weigh L against any other to find out if it is lighter or heavier (3a)

If (2a) doesn't balance it is one of IJK, weigh I v J (3b) If (3b) is now balanced it was K, refer to the side of unbalance in the previous weighing (2a) for lighter or heavier. If the scales are tilted to the same side it is I, so if I is up it is lighter if I is down it is heavier. If the scales tilt the opposite direction it is J and again look at if it is high or low to work out lighter/heavier.

If (1) is unbalanced the different weight is one of ABCDEFGH, weigh ABE v CDF (2b) If (2b) is balanced it is either G or H, now try G v L (3c) if it is balanced H is odd and the results of (1) will tell you lighter or heavier. If (3c) is unbalanced G is odd and lighter or heavier is trivial.

If (2b) is tilted to the same side as (1) the odd ball is one of ABF, weigh A v B (3d) If it balances see a previous weighing to find out if F is lighter or heavier. If the balance remains tilted the same way as (2b) A is odd or if the balance changes tilt direction B is different in either case lighter/heavier is trivial.

If (2b) tilts to the opposite side to (1) one of CDE is odd, weigh C v D (3e) If (3e) balances check previous weightings to see if E is lighter or heavier, if it stays tilted the same way as (2b) D is different, if the tilt direction swaps C is different, in either case it is again a simple case of direct observation to work out lighter/heavier.

Goodnight all, tomorrow I will hopefully draw a tree diagram to clarify that and edit it into the post, unless someone tears this appart, in which case one of you guys will steal my hard work and post a correct answer before I get a chance to correct myself.

or is the answer $3--initial cost of item $7, final sale price $10. makes about as much sense any way you look at it. The simple answer is, he's an art dealer. No one else would pay more than their retail price to repurchase something they already took a profit on...

Point is, you guys love these little math puzzles and proving how smart you are. But real logic has nothing to do with math. Real math has little to do with logic. And neither has anything to do with intelligence. Riddles have answers that cannot always be arrived at by logic. For example: what has four legs in the morning, two legs at noon, and three legs at night?

I'm sure you've all heard the answer to this one, but the answer requires a metaphorical leap before the logic makes sense. But the answer is still a REASONED and REASONABLE answer. So how are you going to prove you're a League of Reason by playing riddle games? Answer that both logically and reasonably if you want the ultimate proof of self.

cri8r wrote:or is the answer $3--initial cost of item $7, final sale price $10. makes about as much sense any way you look at it. The simple answer is, he's an art dealer. No one else would pay more than their retail price to repurchase something they already took a profit on...

Point is, you guys love these little math puzzles and proving how smart you are. But real logic has nothing to do with math. Real math has little to do with logic. And neither has anything to do with intelligence. Riddles have answers that cannot always be arrived at by logic. For example: what has four legs in the morning, two legs at noon, and three legs at night?

I'm sure you've all heard the answer to this one, but the answer requires a metaphorical leap before the logic makes sense. But the answer is still a REASONED and REASONABLE answer. So how are you going to prove you're a League of Reason by playing riddle games? Answer that both logically and reasonably if you want the ultimate proof of self.

Do I detect a note of hostility mingled amidst all that arrogance and condensation?

Our prefrontal lobes are too small. Much too small. That's a problem of the birth canal, I'm very sorry to say for those that like their birth canals... tight.-C. Hitchens.

cri8r wrote:Point is, you guys love these little math puzzles and proving how smart you are. But real logic has nothing to do with math. Real math has little to do with logic.

Right, so it's established you're refering to mathematical puzzles? Great.

cri8r wrote:Riddles have answers that cannot always be arrived at by logic. For example: what has four legs in the morning, two legs at noon, and three legs at night?

I'm sure you've all heard the answer to this one, but the answer requires a metaphorical leap before the logic makes sense. But the answer is still a REASONED and REASONABLE answer.

Not a mathematical puzzle!

Seriously, at least try to be consistent. Maths isn't up for interpretation, it's not mystical and it doesn't require metaphorical leaps of logic, it deals ultimately with demonstrable units that are quantifable and easily proven.

cri8r wrote:So how are you going to prove you're a League of Reason by playing riddle games? Answer that both logically and reasonably if you want the ultimate proof of self.

Why would be play with riddles and maths puzzles? Oh, I don't know....because they're fun? They're interesting? They give the old brain a nice work out? You choose. Not everything needs an underlying subtext, riddles and puzzles are fun. You don't need to intellectually analyse a jigsaw puzzle.

Besides, and I'm getting tired of repeating it, the title League of Reason is tounge in cheek, it's a bit of a joke, a humours counter point to the blatant unreasonable nature of the people we have encounters with; i.e creationists. Seriously...

Because if one does not loosen the facts of the riddle, imagine hypothetical situations that are beyond the norm, nor reason probable solution, then it follows that one will not be able to effectively answer the riddle.

Did we ever get a formal reply on the banker game theory, or have I just missed it?

Anyway, another quick puzzle, I haven't spotted this one in the thread yet.

Imagine a block of marble being transported on some logs. The logs each have a circumference of 1m. If the logs are rotated (simultaneously) such that they perform one full revolution, how far has the marble slab moved?

Support bacteria - they're the only culture some people have.Scientists never grow up, they just get bigger toys.

Undeath wrote:Imagine a block of marble being transported on some logs. The logs each have a circumference of 1m. If the logs are rotated (simultaneously) such that they perform one full revolution, how far has the marble slab moved?

Pi meters! Right?...

Also, HE MADE IT! WAHOOOO! Lets go for 20, while I catch up on the unresolved problems of this thread...

Undeath wrote:Imagine a block of marble being transported on some logs. The logs each have a circumference of 1m. If the logs are rotated (simultaneously) such that they perform one full revolution, how far has the marble slab moved?

Pi meters! Right?...

No, the logs have a circumference of 1 m, meaning the diameter is 1/ Pi m. That factor has already been accounted for.

Support bacteria - they're the only culture some people have.Scientists never grow up, they just get bigger toys.

Undeath wrote:Imagine a block of marble being transported on some logs. The logs each have a circumference of 1m. If the logs are rotated (simultaneously) such that they perform one full revolution, how far has the marble slab moved?

The answer is 2 meters. The logs move 1 meter relative to the ground, and the block moves 1 meter relative to the logs.

"Religion is a culture of faith; science is a culture of doubt."- Richard P. Feynman

In the bank there were the bank manager, the assistant manager and four supervisors.

The bank vault had several locks. For each lock there was one or more keys, but each key could only open one lock.

The bank manager had complete access to the vault. If he wasn't present, the assistant manager together with any one of the supervisors could open the vault. If neither of the managers were present, any three supervisors could open the vault together.

How many locks and keys were needed? (And how were the keys distributed?)

"Religion is a culture of faith; science is a culture of doubt."- Richard P. Feynman

In the bank there were the bank manager, the assistant manager and four supervisors.

The bank vault had several locks. For each lock there was one or more keys, but each key could only open one lock.

The bank manager had complete access to the vault. If he wasn't present, the assistant manager together with any one of the supervisors could open the vault. If neither of the managers were present, any three supervisors could open the vault together.

How many locks and keys were needed? (And how were the keys distributed?)

Manager has all the keys so can get in by himself. Assistant has all the keys except g so needs a supervisor to get in. The supervisors have a combination of six keys which means at least three need to be present to open all the locks (plus they all have g).

It's Sunday morning. You're in a room with two doors. One of the doors leads to the pub, the other leads to church. You're only allowed to open one of the doors, and then you must go through it, and will spend the rest of your morning there.

There are also two sentries. You know that one of the sentries always lies, and the other always tells the truth. You don't know which is which. You are allowed to ask one question of one of them.

blindley wrote:It's Sunday morning. You're in a room with two doors. One of the doors leads to the pub, the other leads to church. You're only allowed to open one of the doors, and then you must go through it, and will spend the rest of your morning there.

There are also two sentries. You know that one of the sentries always lies, and the other always tells the truth. You don't know which is which. You are allowed to ask one question of one of them.

What question do you ask? (Obviously your goal is to get to the pub.)

That's an easy one. You ask either one of them what the other one will say if you ask him where the pub is.

Perception of reality results in interpretation of reality which results in a deformation of reality.